Can Accutane Be Used for Third Time if Acne Appears Again?

i want to know that can isotretinoin be taken again after having it once for 6 months (BD) and once for 3 months (BD)in last 4 yrs i am 33 yrs old and am suffering from acne. A doctor once made me use ro-accutane in 2008 for 6 month (BD) back then i my acne got better and stayed fine for a couple of years. in 2011 i again suffered from acne, a doctor advised me to use isotretinoin for 3 more months, this time it gave me relieve for few months only. now i am again suffering and am in sever pain.